DE69509772T2 - Shackle - Google Patents

Abstract

PCT No. PCT/SE95/00766 Sec. 371 Date Apr. 7, 1997 Sec. 102(e) Date Apr. 7, 1997 PCT Filed Jun. 21, 1995 PCT Pub. No. WO96/00861 PCT Pub. Date Jan. 11, 1996A coupling link (100) to be interconnected between a hoisting device and a shortenable hoisting chain (54,55,56) is provided. The coupling link is elongated and comprises a connecting portion (110) in the form of a loop for connection to the hoisting device and an anchoring portion (150) for anchoring of an end link (51) of the hoisting chain. A selected link, namely a support link (55), of the hoisting chain is inserted in a support slot (132) between two support shanks (131a, 131b) of the coupling link, and a hoisting chain link adjoining the support link, namely an engagement link (54), will make contact, at an end portion thereof, with corresponding seating surfaces (133a, 133b). The loop portion (110) defines a free internal space (111), which is dimensioned to enable pulling through the hoisting chain (50) for adjustment of its effective length and which directly adjoins the support slot (132).

Description

The invention relates to a coupling link for interposition between a lifting device and a shortenable lifting chain. Such a coupling link can be used, for example, for connecting a ring or the like at the end of a chain hanging from a lifting crane to a shortenable lifting chain equipped with a lifting hook at its other end. It is desirable to be able to adjust the effective length of the lifting chain, for example to adjust the vertical position of the lifting hook so that a load can be suspended or to create a lifting chain loop around the load.

A coupling link of this type is previously known from WO 83/03649 (Parsons Controls Ltd) and comprises a connecting region for connection to the lifting means and an anchoring region for anchoring an end link of the lifting chain. Furthermore, the coupling link, which is referred to in the publication as a "shortening clutch", comprises two support legs with an intermediate support slot for receiving a selected lifting chain link, hereinafter referred to as a "support link", whereby a lifting chain link adjacent to the support link, referred to as an "engaging link", engages at an end region thereof in corresponding seating surfaces formed in the support legs. The lifting chain is thus secured in a shortened arrangement in the coupling link.

However, the previously known coupling link has a number of disadvantages. If it is to be connected to a lifting device is to be connected to a larger ring-shaped link, referred to in the publication as the "main link", it is necessary to use both a shackle, the pin of which is inserted through a connecting eye in the upper part of the coupling link, and another coupling link, at least in the case where two or more shortening coupling links are to be connected to the main link.

Furthermore, in the previously known coupling link, the connecting eyelet for the shackle pin, the corresponding connecting eyelet for anchoring the end link of the lifting chain and the support legs are located at the corner points of an imaginary, essentially regular triangle. The support legs are arranged in such a way that the support and engagement links of the lifting chain are freely accessible from the outside when the coupling link is operated and loaded. This entails the risk that these links will be released from the engagement under the influence of blows and impacts, or will be deformed and get stuck, or that the links and/or the support legs will break if they are operated roughly. The above-mentioned triangular arrangement also results in a significant inclination of the coupling link when the load is shifted from the end link to the engagement link of the lifting chain.

The previously known coupling element also comprises a voluminous and heavy structure, which makes production complicated and expensive.

The aim of the present invention is therefore to provide a coupling link of the type defined in the preamble of the appended claim 1, which requires fewer or no coupling links for interconnection with a lifting means, which ensures a protected positioning of the supporting and engaging links of the lifting chain in the engaged position and which has a simple and lightweight construction. The coupling link The coupling link should also be easy to use and suitable for a wide range of applications. It should also be able to be manufactured using conventional technology at low cost. The design should preferably be such that the coupling link is only slightly inclined, if at all, when it is loaded.

These objects are achieved according to the invention in that the coupling link is elongated and comprises: a first end region which is designed as a ring region which forms the connection region, a central region which is equipped with the support legs and the support slot, and a second end region which forms the anchoring region, the ring region defining a free inner space which is dimensioned to allow the lifting chain to be pulled through in order to adjust its effective length and which is directly adjacent to the support slot of the central region, and in that the ring region, the central region and the anchoring region of the coupling link are made from a piece of a link body which has a leg thickness which significantly exceeds that of the links of the associated lifting chain.

Due to the elongated structure of the coupling link and the dimensions of the ring area, the coupling link can, if desired, be connected directly to the lifting device, in particular without the interposition of separate coupling links, since the ring area accommodates part of the lifting device. This can be achieved in a particularly simple way if the coupling link has a fork-like structure that forms the central area and the anchoring area, with two separate legs that can be slipped over the part of the lifting device.

The support legs, which are equipped with seating surfaces in the middle area of the coupling link, border directly on the ring area and ensure that the support and the gripping links of the lifting chain are arranged in protected positions during engagement so that the links and the cooperating support legs of the coupling link can be kept intact without being damaged, even in the event of possible careless operation of the lifting chain. The operation procedure is also particularly simple. When the effective length of the lifting chain is to be changed, the links of the lifting chain are passed through the ring area and when a desired length has been reached, it is only necessary to press the particular link down between the support legs as a supporting link, whereupon the adjacent link engages the seating surfaces of the support legs as an engaging link.

The elongated design of the coupling link makes it possible to connect two or more coupling links directly to the same lifting device, e.g. an oval ring, without any risk of the associated lifting chains interfering with each other. In addition, the inclination of a coupling link after loading is limited, especially when the two end regions of a coupling link are essentially in the same plane or in different planes forming a small angle between them.

The coupling member according to the invention can be manufactured in a relatively simple manner by forging a round bar of iron essentially in a U-shape, with a widened ring area, and subsequently machining it to produce seating surfaces, recesses, bores and the like.

As defined more precisely in the appended claims and the following detailed description, the coupling member according to the invention can be designed in various ways. Furthermore, it can be combined with other coupling members. For example, it can be permanently connected to an oval ring which acts as a lifting means and is introduced into the ring area of the coupling link at the time of manufacture and is then closed, e.g. by welding. If desired, the coupling link can be indirectly connected to a number of rings which are connected in a similar manner to other similar coupling links.

The invention is explained in more detail below with reference to the attached figures, which illustrate various embodiments.

Fig. 1a is a side view of a lifting chain which carries a lifting hook at its lower end and is shortened at its upper end by engaging a coupling link according to the invention, which in turn is connected to an oval ring;

Fig. 1b shows the same lifting chain, the same lifting hook and the same coupling link as in Fig. 1a, although the lifting chain is arranged in a different way;

Fig. 2 is a plan view of the coupling link (without chain), and Fig. 2a shows a modified embodiment of the anchoring region of the coupling link;

Fig. 3 is a sectional view taken along the line IIT-III in Fig. 2 (with some of the lifting chain links indicated by dash-dotted lines);

Fig. 4a is a sectional view taken along the line IVa-IVa in Fig. 3, and Fig. 4b is a sectional view taken along the line IVb-IVb in Fig. 3;

Fig. 5 is a side view of a modified embodiment of the ring portion of the coupling member;

Fig. 6a, 6b, 6c and 6d show further modifications of the ring area with external connecting projections ;

Fig. 7 is a side view of a second embodiment of a coupling member according to the invention;

Fig. 8 is a sectional view taken along the line VIII-VIII in Fig. 7;

Fig. 9 and 10 show a modified embodiment of the anchoring region of the coupling member according to Fig. 2 and Fig. 3;

Fig. 11 shows a modified embodiment of the ring area of the coupling link with an integrated hook part;

Fig. 12 shows a further modification of the ring area with a closable hook part;

Fig. 13 is a cross-section through the oval ring at the top of Fig. 1;

Fig. 14a and Fig. 14b are sectional views of the eyelet region of a lifting hook and a fork region of a coupling member according to the invention, respectively;

Fig. 15 shows the same combination as in Fig. 14a and Fig. 14b, with the lifting hook shown in a side view;

Fig. 16a and Fig. 16b show the ring portion of the coupling link with external projections connected to the end link of a chain;

Fig. 17 shows a modified embodiment in which the ring area is externally connected to a larger link or ring;

Fig. 18 and 19 show a coupling member and a permanently connected larger ring;

Fig. 20 shows two coupling links permanently connected to a larger, common ring; and

Fig. 21 shows a combination comprising one large ring, two small rings and four coupling links, each with a lifting chain.

The coupling member 100 shown in Fig. 1, 2 and 3 is connected at its upper part to an oval ring 10 (see Fig. 13) which serves as a lifting means and is connected, for example, to a chain, a lifting belt or a hook suspended from a crane, an overhead crane or any other lifting or pulling device. The oval ring 10 has on a longer side a flattened portion 11 whose cross-sectional area is substantially the same as that of the other cross-sections of the ring, but whose width is dimensioned to fit with some play between the separated legs of the coupling member 100 (bottom of Fig. 2). After removing an anchoring pin 190, the oval ring 10 is inserted into the coupling member 100 in the position shown in Fig. 1a and 1b. The coupling link carries a lifting chain 50 at the bottom, one end link 51 (the upper end link in Fig. 1a and 1b) of which is anchored to the anchoring pin 190 of the coupling link, and the other end link 59 (the lower link in Fig. 1a and 1b) of which is connected to a lifting hook 80. The purpose of this arrangement is to enable convenient adjustment of the effective length of the lifting chain by selecting a desired pair of links, which is a support link 55 and a handle member 54 is engaged in the coupling member 100, as shown in Fig. 1a, 1b and 3.

The lifting chain 50 can be pulled through the coupling link 100 in a single position, i.e. with one part, as shown in Fig. 1a, or in a double position, i.e. with two parts, as shown in Fig. 1b. Alternatively, the lifting chain can of course hang directly from the anchor pin 190 (see Figs. 18 and 19). From this position it is easy to change to the adjustable arrangement according to Fig. 1b, whereby a double or U-shaped loop is pulled through the interior of the coupling link. When changing to the arrangement according to Fig. 1a, which is a permanent shortening arrangement, one must, on the other hand, insert the lifting chain 50 into the coupling link 100 before anchoring the end link 51 thereto.

The coupling member 100 is elongated and comprises a first end region 110, a middle region 130 and a second end region 150 (Fig. 2).

The first end portion 110 is intended to be connected to the ring 10 or any other lifting means and to allow one or more parts of the lifting chain 50 to be pulled through. For this purpose, it is ring-shaped with a well-defined interior space 111 dimensioned to allow such pulling through. The ring portion 110 is defined by the upper, widened portion of a forged, substantially U-shaped link body 101 having an upper, slightly rounded ring top portion 112, adjacent ring side portions 113a, 113b and ring bottom portions 114a, 114b.

Approximately in the middle area 130 of the coupling link, the ring sub-areas 114a, 114b merge into separate support legs 131a, 131b, which are shaped to support and to carry and engage with engagement members 55, 54.

In the other end region 150 (the lower one in Fig. 2) the support legs 131a, 131b merge into separate end or anchoring legs 151a, 151b, which have mutually corresponding openings 152a, 152b for supporting and securing the anchoring pin 190, through which the end link 151 of the lifting chain can be anchored to the coupling link.

In this embodiment, the support and end legs 131a, 151a and 131b, 151b respectively form separate legs of a fork region which allows the introduction of a ring 10 or any other lifting means so that the coupling member can be connected to and detached from the means after removal of the anchoring pin.

The support legs 131a, 131b have a gap between them, referred to below as support slot 132, the width of which slightly exceeds the material thickness of the lifting chain links, so that such a link, i.e. the support link 55, is received in the standing position with some play between the support legs 131a, 131b, i.e. with the main plane of the support link 55 aligned perpendicular to the extended plane of the ring area 110 of the coupling link. The support legs 131a, 131b have internal recesses which form concavely rounded seating surfaces 133a, 133b, the geometry of which is adapted to the outer end regions of the lifting chain links on each side of the longitudinal center line of the respective link, so that the engaging link 54, which is adjacent to the support link, makes surface contact with its outer end regions on these seating surfaces 133a, 133b. Compare the section in Fig. 4a, where the curvature of the seating surfaces, corresponding to the end region of the link 54, is clearly visible.

The first and second end regions 110 and 150 are arranged in different planes in the embodiment according to Fig. 1, 2 and 3, the extended plane of the other end region, i.e. the anchoring region 150, being inclined by approximately 30° in relation to the extended plane of the first end region, i.e. the ring region 110. The angle of inclination can vary somewhat, but is preferably within the interval 20°-60°. This angled structure provides the advantage that the support member 55, which is located between the support legs 131a, 131b, can be aligned with its longitudinal axis in the same plane as the first end region of the coupling member or the ring region 110. This in turn means that the lifting means or ring 10, the ring portion 110 of the coupling link and the lifting chain 50 can be aligned along a straight line when under load.

In order to enable such an alignment of a support member 55, the support legs 131a, 131b are equipped with recesses 134a, 134b (see Fig. 2, 3 and 4b) on the side opposite the seat surfaces 133a, 133b, which accommodate a region of the end part of the member 56 that adjoins the support member 55. Since these recesses 134a, 134b must be arranged at a small distance from the seat surfaces 133a, 133b, corresponding to the free distance between the end regions of the members 54 and 56, the support legs 131a, 131b of the central region 130 form arcuately extending material regions, of which only one, i.e. 135b, visible in Fig. 3 .

Furthermore, the dimensions of the anchoring region 150 are such that the support member 55 can rest with its lower end region on the end member 51, which is anchored to the anchoring pin 190.

As shown in Fig. 2, the anchoring pin 190 can have a head 191 at one end and a locking nut 192 at its other end. Alternatively, as shown in Fig. 2a, the anchoring pin 193 can have annular grooves 194a, 194b at its end regions, these grooves cooperating with locking pins 195a, 195b driven into four openings in the anchoring legs 151a', 151b'.

The basic embodiment of the coupling member according to the invention, as shown in Fig. 1-3, can be modified in many ways within the scope of the invention. The ring area 210a, see Fig. 5, can have a straight ring top 212a for suspension on a lifting belt, in particular a belt made of synthetic fiber. It is also possible to equip the ring area 310a, 310b, 310c, 310d (see Fig. 6a-6d) with external projections or lugs 315a, 315b, 315c and 315d, respectively, which are made in one piece and have mutually matching openings for connection to a shackle, a coupling part or directly to a lifting means. The projection can alternatively be formed by a hook part 416, which is integrated in the ring area 410 (Fig. 11), or by a rigid hook leg 416a, which cooperates with a hook part 416b, which is pivotally mounted on the ring area (Fig. 12).

Fig. 16a and 16b illustrate how the ring portion 510 with lugs 517 formed thereon and having openings can be directly connected to a lifting means in the form of an end link 20 of a (upper) lifting chain. Fig. 17 shows a direct connection of the ring portion 610 of a coupling link to an oval, large link or ring 30, with a connecting pin 619 arranged in lugs 618 having matching openings.

As shown in Fig. 14a, 14b and 15, the coupling link can be connected to a lifting hook 40 by inserting a coupling eye portion 40a having a flat part 40b between the fork legs 160a, 160b of the coupling link. For this purpose, the thickness of the flat part 40b is slightly less than the distance between the fork legs 160a, 160b. Such an arrangement can be used, for example, at the bottom of a lifting chain (e.g. instead of the end link 59 and the hook 80 in Fig. 1), so that the length of the lifting chain can be adjusted at the bottom of a coupling link connected to the lifting hook. Such dimensions of a lifting hook (its eyelet area) and the coupling link result in increased safety, in that a lifting hook 40 that is too large is equipped with a flat area 40b that cannot be inserted into the gap between the fork legs 160a, 160b, and a lifting hook 40 that is too small is equipped with a coupling eye 40a that does not accommodate a fork leg 160a. Only lifting links that are essentially dimensioned for the same loads can therefore be connected together in this way.

In Fig. 7 and 8 a second embodiment of the coupling member 700 is shown, wherein both the first and second end regions 710, 750 and the central region 730 extend in a single, common plane. The ring region 710 is substantially similar to that in the embodiment according to Fig. 1-3, and the anchoring region 750 corresponds to the embodiment according to Fig. 2a (although in the same plane as the ring region). The central region 730 is, however, differently designed with a web-like region 740 which interconnects the support legs 731a, 731b and which forms a supporting lower surface 741 for the support member 65 which is located in the support slot 732, the support member being aligned with its longitudinal axis perpendicular to the extended plane of the coupling member. On each side of the support slot 732 the support legs have both obliquely inclined te support surfaces 742a, 742b, which form a support for the lifting chain link 66 adjacent to the support member on the load side, as well as concavely rounded seating surfaces 733a, 733b for supporting the end part of the engagement member 64 over the entire surface. The lower part of the web-like region 740 is recessed in order to receive the next link 67.

In this case, the coupling link 700 is positioned with some inclination, but the inclination is moderate because the coupling link is elongated and the link 67 (which is aligned with the lifting chain under load) is positioned adjacent to the anchored end link 61.

As shown in Fig. 9 and 10, an angled coupling member 800, which has jointly angled end regions as in Fig. 1-3, can also be equipped with a web-like region 840. With respect to the embodiment according to Fig. 1-3, there is also a difference in that the middle region 830, which has support legs and a web-like region, has a slightly longer extension.

Finally, Figs. 18-21 illustrate how one or more coupling links 100 can be connected to a lever means in the form of a large oval ring 10', which in this case is manufactured together with the coupling link and is permanently connected to the latter, e.g. by forming the ring by welding a blank after the blank has been hooked into the ring area of the coupling link. In the initial position, only the end link 51 of the lifting chain is anchored to the anchoring pin 190 of the coupling link, but after the anchoring pin is attached, the lifting chain can be pulled through the ring area and secured with selected support and engagement links in a similar manner to Fig. 1a.

In Fig. 18 and 19 only one coupling link 100 is connected to the ring 10' in this way, in Fig. 20 there are two coupling links 100 angled in opposite directions and permanently connected to the ring 10', and in Fig. 21 there are four coupling links 100 permanently connected to the ring 10' via two intermediate coupling rings 10", each connected to two coupling links 100.

The coupling link described above can be modified and further developed within the scope of the appended claims. For example, the central region of the coupling link can be equipped with a special securing means to hold the supporting and engaging links of the lifting chain in the engaged position. Such securing means are known per se for use in connection with lifting links and can be either automatically self-locking, e.g. by spring or snap action, or manually operated, e.g. by adjusting or rotating a securing element into the securing position.

Claims (23)

1. Coupling link (100) for interposition between a lifting means (10) and a shortenable lifting chain (50), wherein the coupling link has a connection area (110) for connection to the lifting means and an anchoring area (150) for anchoring an end link (51) of the lifting chain and where a selected link, namely a support link (55) of the lifting chain is introduced into a support slot (132) between two support legs (131a, 131b) of the coupling link, and a link of the lifting chain adjacent to the support link, namely an engagement link (54), at the end of which engages in corresponding seating surfaces (133a, 133b) formed in the support legs, characterized in that - the coupling link is elongated and comprises : - a first end region which is designed as a ring region (110) which forms the connecting region, - a central region (130) equipped with the supporting legs and the support slot, and - a second end region (150) forming the anchoring region, - wherein the ring region defines a free interior space (111) which is dimensioned to allow the lifting chain (50) to be pulled through in order to adjust its effective length and which is directly adjacent to the support slot (132) of the central region (130), - and in that the ring region, the central region and the anchoring region of the coupling link are made from one piece of a link body (101) which has a leg thickness of which significantly exceeds that of the links of the associated lifting chain. 2. Coupling member (700) according to claim 1, characterized in that the first and second end regions (710, 750) are located essentially in the same plane and in that the support slot (732) and the support legs (731a, 731b) with the seating surfaces (733a, 733b) are designed such that the longitudinal axis of the support member (65) is oriented transversely with respect to the plane. 3. Coupling member (100) according to claim 1, characterized in that the first end region (110) is arranged in a first plane and that the second end region (150) is arranged in a second plane which is inclined with respect to the first plane, the central region (130) of the coupling member forming a transition between the first and second planes. 4. Coupling member according to claim 3, characterized in that the support slot (132) is oriented such that the longitudinal axis of the support member (55) is arranged in the first plane. 5. Coupling member according to one of claims 1 to 4, characterized in that the support slot (132) and the support legs with the seating surfaces (133a, 133b) are designed in such a way that the engagement member (54) protrudes from the plane of the first end region (110) when it lies in the seating surfaces. 6. Coupling member according to claim 5, characterized in that the seating surfaces (133a, 133b) are formed by internal recesses in the connecting body at the central region (130). 7. Coupling link according to claim 6, characterized in that the support legs (131a, 131b) have inner recesses (134a, 134b) on the side opposite the seat surfaces (133a, 133b) for receiving a chain link (56) adjacent to the support link. 8. Coupling member according to claim 7, characterized in that the seating surfaces (133a, 133b) and the recesses (134a, 134b) of each support leg (131a, 131b) form a material region (135b) extending essentially in an arc between them. 9. Coupling link according to one of claims 5 to 8, characterized in that the support member (55) is held in its position in part by its resting on the end link (51) of the lifting chain at the anchoring region (150). 10. Coupling member according to one of claims 1 to 9, characterized in that the central region (130) and the anchoring region (150) together form a fork region. 11. Coupling link according to claim 10, characterized in that the fork region (130, 150) comprises two separate legs which are equipped with a transverse anchoring pin (190) for the end link (51) at the end of the anchoring region. 12. Coupling member according to claim 11, characterized in that the anchoring pin (190) is removable. 13. Coupling member according to claim 11 or claim 12, characterized in that the anchoring pin (193) is designed to hold the separated legs at a predetermined distance from one another. 14. Coupling member (700) according to claim 10, characterized in that the fork region (730, 750) comprises two legs which are held together by a web region (740). 15. Coupling member according to claim 14, characterized in that the web region (740) forms a support surface (741) for the support member (65). 16. Coupling link (100) according to one of claims 1 to 15, characterized in that the interior (111) of the ring region (110) is so large that it accommodates both a hook-like or ring-shaped region of the lifting means (10) and the lifting chain links (54, 55, 56) with a certain amount of play. 17. Coupling link according to one of claims 1 to 16, characterized in that the interior (111) accommodates two parts of the lifting chain (50). 18. Coupling link according to one of claims 1 to 17, characterized in that the ring region (310a-d) has external projections (315a-d) which are equipped with openings, wherein the projections can be connected to one another by a shackle, a connecting part, a chain link or the like of the lifting means. 19. Coupling link according to one of claims 1 to 17, characterized in that the ring region (410) is combined with an external hook part (416) in one piece. 20. Coupling member according to one of claims 1 to 17, characterized in that the ring region (410) comprises on the outside both a pivotably mounted hook part (416b) and a rigid hook leg (416a) which is designed to hold the hooks Opening to be closed when the hook part is in its working position. 21. Coupling link according to one of claims 1 to 13, characterized in that the distance between the legs (131a, 131b) of the fork area slightly exceeds the material thickness of the lifting chain links (51, 54, 55, 56) and in that this distance also slightly exceeds the thickness of a part (11) of the lifting means (10) that is flattened at one point, so that the latter can be inserted between the legs of the fork area and is thereby connected to the coupling link. 22. Coupling link according to one of the preceding claims, characterized in that the coupling link (100) is permanently connected to an oval ring (10') which forms the connecting means and which is introduced into the ring region of the coupling link during its manufacture and is then closed, e.g. by welding. 23. Coupling member according to claim 22, characterized in that the coupling member is permanently connected to one or more oval rings (10', 10"), which are connected to other, similar coupling members (100) in a corresponding manner.